Paint-remover and process of making the same.



, .UNIIED STATES- PATENT OFFICE.

FRANCIS eovERs-oi OWEGQNEWYORK.

PAIN r-R MovER AND rnocnss o1 MAKING THE SAME.

' art to which it appertains to make and use the same.

This invention relates to paint removers and processesof making the sameand consists in a paint and varnish remover composed of-aphenol,,preierably cresylic acid, and plurality of volatile solvents ofdifferingchemical.character, said plurality preferably comprising anaromatic hydrocarbon and cite of the loweialcohols, said remover beingcolloided by casein dissolved therein with the aid of a limited amountof a concentrated liquid fatty acidj and also in a process-of.-preparing such removers comprising the admixing -ofa phenol with arelatively large amount of a mixture of" a plurality ofvolat-ile"solv.ents and the solution of casein in the mixture so formedby the aid of a little liquidiatty acid; all as niore fully hereinafterset forth and as claimed. V

The phenols'have good softening and disintegrating powers for-paint andvarnish constituents and have also properties which render them suitablefor disin- .i'ecting old and foul walls and furniture-from which paintor varnish must be removed, but alone they are hardly suitableiorpractical paint or. varnish removersas they form liquids rather toothinly fluid-to be localized on a wall and-are corrosive to the hands ofthe.

operator. 'Nor are they'applicable to all paints. and

varnishes or capable of acting upon all the constituents of any onepaint or varnish. Phenols are pr'eferably,

- therefore. used in combination with other solvents of differingchemical character. to produce removers of general applicability andcapable of attacking all constituent-s of any one paint-or varnish.Preferably, also, a plurality of such other solvents differing amongthemselves in chemical character, is employed. F

ther, since these other solvents, like the phenols themhvselv es', aregenerally rather thinly fluid, iorpractical purposes it .is better tocolloid the mixture somewhat by a dissolved colloid body; such. ascasein. For this purpose'nith mixtures containing phenols, casein hasthe great additional practical advantage that being proteid in nature itrestrains the corrosive action of such phenols upon the hands of theuser. Other proteids, like glue and gelatin may be similarly used andare similarly advantageous. For the colloiding effect pm so, however,non-proteid colloids like pyroxylin and gutta percha may be used. But ingeneral it is.

desirable to use at least some proteid in the mixture as a colloidingagent; and. this proteid is preferably casein or a similar colloidproteid. Such a colloided Specification of Letters Patent. Applicationfiled August 9. 1907 Serial No. 387| 831.

.'- Batentd. Oct. 22, i907.-

remover is thick and of little mobility, and for this reason and for thereason that the colloided phenols, in themselves not very volatile, help'to restrain the volatility of the volatile solvents'with which they areincorporated, in use compound removers mad as stated display littletendency. to evaporation even when the remover is,'--as it mustbel inpractice,

spread out in comparatively thin layers upon coated surfaces.

1 have discovered that by employing certain specific I ways of puttingthe described bodies together I can produce new removers of greatgeneral applicability.-

I find that by first incorporating a phenol, preferably cres ol, with anaromatic hydrocarbon, preferably toluol 'in the present embodiment ofmy, invention though benzol or xylol may also be used, and with one ofthe lower alcohols, such as methyl or ethyl alcohol, but preferablymethyl alcohol, einploying-about' equal quantities of phenol,hydrocarbon and alcohol, I obtain a clear solutionbf good paintsoftening and disin-l tegrating powers". I This solution howeveijpcrsc,'is not well adapted to serve as a remover, being too mobile to'permit convenient application in layers of -'etlicient thickness onvertical or inclined walls. While it is possible to colloid the statedsolution with such bodies as pyroxylin or gotta percha,:it is notpracticable to" colloid indirectly with my preferred colloid bodies,-

the proteids such as casein." The solution of-itseli will not dissolvemuch casein, or at least not enough to be of practica value, in anyreasonable time, nor will it even soft 11 casein to any extent. But Ihave found that it acquires the power of dissolving casein upon beingacidulated with a: relatively smallaindi nt 0t .a concentrated liquidfatty acid; such asacetic or formic acid. Upon acidulating the solutionand dis solving casein or other suitable colloid, but preferably casein,therein, I obtain thick,; comparatively clear and homogeneouscompositions of great practical value as paint and varnish removerssince they are not. liable to much loss by evaporation andreadily attackand disintegrate paint or varnish. By reasonof their thick gconsist ency, which is preferably someh'hat greater than the consistency ofcaster oil,'they..are radilyap- -plied with an ordinary paint brush inmuch the same manner as paint. I As stated, the phenol used-ls prefembly ordinary cresylic acid, though carbolic acid may alsobe employed.ln-practice, I. mix the phenol with about. the same quantity of anaromatic hydi'ocarlmn, preferably tolnol, and then add about the sameamount of alcohol. The clear solution so formed, i' n"spite of thcsolventpower of cresylic acid for-casein, dissolves, relati rel y littleof that substance in any convenient. time: this "being probably due tothe restraining action of the tnluol and alcohol. But on adding'zt'l'cwp'cr coat. of a concon tmtcd liquid fatty acid, say 5 per ccut., itbecomes a relatively good solvent for relatively large amountsofcolloids such as casein. Ten per cent. of casein dissolved in theacidulated mixture will give a remover of a consistency rather greaterthan that ofcastor oil. As the lower alcohol employed, I preferably usemethyl alcohol which may be of any of the stronger commercial grades.Ordinary 'wood spirit is perfectly suitable.

A s a practical example of my remover and of the proc-- ess of making,the same, I may adduce the following: Mix about 1600 grams of ordinarycommercial cresylic acid or cresol with 1500 to l600.gran1s of-commercial toluol and the same quantity of. connnercial wood al;

'(ollolp The mixture forms a clear solution. Upon now, .adding about ahalf a kilo of commercial dried casein,

preferably ground to about 120 mesh, it will be found not to dissolve toany extent, at least at first. But

upon adding a small quantity of a concentrated liquid fatty acid, sayabout 5per cent, or, in this case, about 25(lgrams, the casein willb efound to go into solution,

producing a thick transparent or translucent mass of a consistencysomewhat g reater thanthat of-castor-oil.

The slatedainount of casein is about per cent. of the before thecaseinis added, but I prefer to add whole mass. The solution isfacilitated by warming or by violent stirring; the latter, because of'thethickconsisteucy, being best performed by some commercial form ofstirring-apparatus. If the remover is desired somewhat thicker a littlemore casein may be em ployed; if somewhat thinner, a little less. Butfor most purposes, 10 per cent. will give about the right consistency. v

Glue or other proteids may be used to replace part or all of the casein,but I 'prefer casein. Part or all the cresylic acid may be replaced bycarbolic acid, but I prefer the former. Either acetic or formic acid maybe well employedas the concentrated liquid fatty acid,

but in the present embodiment of my i ivention, I-pre-- fer formic acid.While a portion of t 1e volatile so1' vents, alcohol or toluol, may le='added after the solution of the casein, I prefer to mix the totalquantityof such solvents with the phenol before attempting-to dissolvethe casein. The liquid fatty acid may .116 added t 1e casein first asthe operation is rather smoother. The relnoverprmluced is substantiallya mixture of about equal parts of a phenol, such as'cresol, an aromatichydrocarbon, such as toludl and a lower alcohol. such as methyl alcohol,colloided and give-ll consistence by the presence of about l0 per cent.of colloid, calculated on the ioi al mass, with enough liquid fatty acidto hold the colloid in solution, say about. 5 per cent. of the totalmass. Theseproportions may oi'coum be varied a little one way or anotherbut those stated are practical and satisfactory, producing a remover-ofgood paint softening and disintegmtiug powcr which can bc powers,rendering'it eminently suitable for treating old coated surfaces, whilethe proteid present restrains the action of the phenol upon the hands ofthe user. The presence of acetone in the wood alcohol employed is notinjurious'for the present purposes.

1. The process of producing a paint and varnish remover which comprisesmixing a phenol with one of the lower alcohols and with an aromatichydrocarbon and in then dissolving casein in the mixture with the aid ofa small amount of a liquid fatty acid.

2. The process of producing a paint and varnish remover which comprisesmixing cresylic acid with an aromatic hydrocarbon and with one of thelower alcohols, and in then dissolving casein in'the 'mixture with theaid of a small amount of a liquid fatty acid.

5. The process of producing a paint and varnish remover which comprisesmixing cresyiic acid with tolu'ol and ture with the aid of'a smallamount: of conccntratcd formic acid.

5. The process of producing a paint and varnish remover which comprisesmixing a phenol with an aromatic hydrocarbon and a lower alcohol,mixing'casein with the mixture, acidulating said mixture with asmallamount of a liquid fatty acid to cause a solution ofthe casein, anddissolving the casein.

6. As'a paint and varnish remover, a thick mixture of a' phenol, anaromatic hydrocarbon and one of the lower alcohols in about: equalproportions, said remover containing about 10 per cent.of-dissolved-cascin as a coliolding agent and a little liquid fattyacid.

7. is a paint and yarnish remover} a thick mixture of cresylic acid, anaromatic hydrocarbon and one of the lower alcoholsin about equalproportions, said remover containing about 10 per ccntfof dissolvedcasein as a col-- I loidlng agentnnd a little liquid fatty acid. v 8. Asa. paint: and varnish remover, a thick mixture of cresylic acid, toluoiand one vof the lower alcohols in about e ual proportions, said removercontaining about '10 per cont. of dissolved casgriii us a -colioi'dingagent and a,iittie liquid fatty acid.

9. As a-pulnf and varnish remover, a'thick mixture of crcsylic acid.toluol and methyl alcohol in about equal proportions. said rcmovcrcontaining about '10 per cent. of

dlssoh'cdcascln as a colioiding agent and a litt'lcliquid fall acid.

-10. As a paint and varnish remover, a thick mixture ot crcsyllc acid.toluol and methyl alcohol innbout equal pro- |N rli0n. ',.s1lid rcmovcrcontaining anout' 10 per-cent. of illssolvul casein as a colloidingagent and a little ,concens Irutcd 'iorlni'c acid.

In lcsllmony whereof, I aflix my signature in the presl-m'c olf twosubscribing witnesses. 4 l FRANCIS X. GOVERS.

\\' ltucsses K. I. ilicELuox, C. W. Fownnu.

